Nero burning speed??

I am running Nero v6.3.20 and for some reason the ONLY option it allows mne to burn at is 4x with 4x media, however I would like to slow it down to 2.4x etc sometimes. Is there a setting I can change so I have the option to pick my burn speed?

Yes...my burner is a 16x writer and the media is 4x. I can write no problem at4x but I want to lower it to 2.4x or so. This should not have anything to do with the media nor the burner speed as they would both support a "Lower" speed, correct?